Hardy-Weinberg Principle

Understanding allele and genotype frequency in population in Hardy-Weinberg Equilibrium.

[@MacieJay]

You explained it exactly as my teacher, thanks for the review!

[@gothcoffeedrinker420]

this guy has been helpful through 3 semesters of bio its amazing how he makes it all click

[@richisnang1]

bloody amazing, people have been trying to teach me that for a whole year now, and now in just 15 mins it makes perfect sense. HOW ARE YOU SO GOOD!! thanks very much :)

[@AmanKumar-yu5jb]

I really love the way of teaching here!!

[@AllahCreatedMe]

I wasted a day trying to get this! Thanks so much for helping me get it so i can enjoy the remaining portion of the weekend!

[@xxprincesszeexx]

Thank you, thank you so much. I can't even begin to tell you how useful this was.

[@simonadeutsch5680]

hey guys ohmymymymy i looooove this topic!! but honestly his handwriting is sooooo goals.... like i love it sm.....ohmygod i can't even

[@ATMfromNJ]

Better than my medical school's biochemistry teacher! Great work Khan Academy!

[@evo3711]

What even is Hardy Weinberg equilibrium and why do we make all these assumptions about a given population? If it's based on so many assumed things, how can the numbers be accurate? Or is it not supposed to be accurate?

[@luciekimber7255]

Yeah! I have same questions too...

[@KeenCode]

Well made and easy to follow. Covers just about everything you need to know for exams

[@AintNobodyAskYou]

Taught me WAY more than my biology teacher ,, Thanks a million!

[@lwarfield52]

Thank you, Mr. Anderson. Excellent.... video. I am excited and not understand this process for class. Way to go! (:

[@FatalMindedMe]

This was an extremely useful revision tool! Thank you very much for posting it ^-^

[@iota1122]

Keep P dominant and q recessive. There are other stat. formulas in population genetics that will call for one or the other; and most textbooks list the the formula as P^2 + 2pq+ q^2=1. Hope this helps, cheers.

[@michaelbradshaw9381]

Thank you! I'm a 2nd year med student, you are articulate and succinct. Job well done!

[@ChiragSonne]

me too

[@721bmx]

You guys literally have every subject its great

[@MNflysociety]

I pay 23k a year for an education and I find myself learning more from KZbin than my professors. FML. Thanks Khanacademy.

[@SoorajSuseelan10001]

This is your 12 year old self commenting. I wonder how you will be feeling when I invoke your attention now 😊

[@loz764]

wow that was brilliant, finally some genetics i actually understand!!!! thankyouuuuu :):):)

[@Sn0wFreak]

You are amazing...better than soooooooooo many teachers at explaining things...the education system should be full of teachers who can actually explain things to idiots like me!

[@FaerieDust]

I can't believe how easy that was. Also can't believe how our teacher could make it seem so incredibly difficult that we all struggle with this O.o am sending this link to everybody in my class xP

[@ogtej]

Wow just made so much more sense than my class! Thanks!

[@tracks_]

THANK YOU FOR POSTING! i gotta bio test coming up thats gonna be a bitch and my books making no sense at this point. once again, thank you

[@djennym3960]

isn't P the freq. of the homozygous dominant allele but why did he calculate the freq. of BB using q instead of p?

[@sadeedmusabbir7856]

Very well explained. helped me a lot thank you

[@Julie-fh5gi]

khan academy is a grade saver, thank you

[@passionatesilence]

I don't understand the logic behind this, but you have a very nice voice and it makes it easier to follow your train of thought...

[@DarkMysteryCat]

Thanks a lot! I was quite confused about this principle, but now I get it.

[@boxermitro]

Thank you very much! Great work!

[@josieladle5092]

It doesn't matter what the notation is, as long as you don't switch it in the middle of the problem. It's really not confusing at all, he explains it very well.

[@Aelfraed26]

Words can't express how grateful I am.

[@minahilkhattak4047]

Omg i have been depressed and kind of crying for last 2 hours because i have my medical entrance test after 7 days and i couldnt understand this, you made it so easy Thanks Khan academy

[@Imran-cf9cs]

Mdcat?

[@bigsword33]

Guys, unless your teacher explicitly states it, which one you designate as p or q hardly really matters. Once you go into the harder problems you lose total dominance and you'll start working with more than one allele per situation. Conceptually p and q are just variables,they can be whatever you want them to be.

[@Brinn18844]

love you're handwriting :D

[@sn321097]

hahaha, u need to be my AP bio teacher, this was sooooo helpful

[@madhavimothkuri]

your lecture is very good ,thank you.

[@jeffreysuzuki3065]

Keep up the good work.

[@jenniferchu3443]

p is the frequency of the dominant allele in a population, just saying.. bb (blue eyes) is a recessive trait..

[@bobross3356]

it doesn't matter if you represent it

[@lola-sk1dd]

@@bobross3356 oh but it does matter if ur teaching ppl that are already a bit confused u had me wondering wat i was doing wrong for a sec

[@dfsfklsj]

Khan, I want to make a request: Apparently this is more statistics related to this topic(chi-square distributions), so can you make video(s) on the statistics part? Thanks

[@veronicaarnold832]

My biology books makes it out to be so much more confusing then it needs to be, but this video explains it very clearly.

[@bhanumahajan8344]

Loved the video-

[@nishabilkhiwal997]

I wanted to know how those 5 factors affect this principle and off course those graphs- directional etc.

[@jazgriffin15]

this is so helpful, but how would you predict the genotype frequencies and the allele frequencies for the next generation?

[@Smilllerr]

Thank you so much for this! This is so usefull!

[@mikelmanson]

Could you tell me the specific Wacom Bamboo Tablet model you're using to make this great videos? Thanks

[@RiekeDobo]

I love your handwriting. You're very good at explaining though I still do not understand it. I'll watch it later again, it's too late too be focussed.

[@anuradhapandit9824]

so all of this is assuming that the population IS in an Hardy Weinberg equilibrium, right?

[@Jchachas]

you legit saved my life

[@Peterross111]

THANKS!!! Well, if only my whole A-level was this easy :p

[@cursedu]

helpful ty this will help me for my test tommorw ty boss

[@aleemshaan]

Which software did u used??? Its really amazing. . .

[@Monokuro92]

this video was really helpful, but it does assume some prior knowledge of certain terms (homozygous, heterozygous, hybrid, allele, phenotype, genotype ect.) so while very helpful for myself and others who have some of this prior knowledge - might be a bit confusing for people just starting off in the subject. it might be a good idea for said people to look up some of these terms, and put a little research into allele/phenotype frequencies - and hopefully this video will be much more helpful :)

[@Sir1Snorteaus]

Thank you, Khan!

[@blackandwhitepiano1]

Fantastically usefull!

[@CasperWK]

the one thing i dont understand is why there arent more teachers like you out there

[@robertschmink4289]

So in hardy-weinberg problems, do we assume that there is either no variation or that the variation is negligible? Is that a correct understanding?

[@healthfreak18]

This is great! Thanks so much!

[@jasenkim22]

you sir are a hero

[@ahmedst]

Thank you! Greatly appreciated!

[@soliellieben]

very well explained.great teacher..which software is used here?

[@dakingcool]

Can you explain this one to me 100 people are typed at a biallelic ( 2 alleles) locus with allelic frequencies of p=0.6 and q=0.4. Assuming Hardy weinberg equilibrium, how many are hetrozygous (explain working out please)

[@TheMahirahmed07]

Very Important! The dominant allele frequency is represented by p and the recessive allele frequency is represented by q.

[@fcksckdmn]

how do you do when you have a gen with 4 alelles?

[@Juigi33]

Goodjob, thanks for the help

[@anweshpanda7417]

nicely explained

[@12chultm]

thank you so much!!! this was so helpful!!!!! :D

[@Thehelpfuldude]

I have a question, my teacher uses "q" for recessive and "p" for dominant alleles, is that the same thing??

[@fingertaping]

wow, a week in Bio 30 class didn't teach me anything, but 15 minutes at my computer taught me the whole damn thing!!!

[@ZeroKelvin]

Great video and explanation. The only complaint I have is the cursor; it's very distracting and at some points makes me dizzy. Thanks again though.

[@Alinask84ever16]

Could you please tell me what software u use ? I love it.

[@OriginalShuffler]

Looks like it's simply Microsoft Paint.

[@triggertheoriegroupy]

I don't think it matters what P and Q are, recessive or dominant etc. It all adds the same, aslong as you state what you've used P and Q for, then it shouldn't matter.

[@Wil_87]

+triggertheoriegroupy the maths will tally, but convention says that p = Dominant and q = ressessive

[@kkon8966]

It matters when a student learns something incorrectly

[@Olympics1001]

this is very helpful thanks

[@smashadams9811]

Well, how much do you already understand about p and q?

[@siobhaneaston9779]

Very helpful thanks!

[@mslizziey8]

This is so helpful!

[@menaleaus]

@itsthefantasy the results will be the same, but sometime in your studies a question stem may specify 'homozygous dominant' and ask for you to match the variable. This is what happened to me as I was studying for the MCAT... otherwise, especially on the basic level of studying, I guess it doesn't make a difference.

[@lilyjune1230]

this is really helpful!!!!!

[@omochii123]

Although, isn't p the frequency of the dominant trait and not the recessive trait? And the same for p^2 + 2pq + q^2? I was just wondering. Seems strange that you switched them.

[@Femzstar]

they may be a mistake here, but i dont know. Isn't the P meant to represent the dominant allele and q the recessive allele or doesnt it matter?

[@refath522]

I have a problem with this question; In a population of certain frogs in which the allele for brown skin is dominant to the allele for green skin, a drought leads to selection against green-skinned frogs. When the drought ends, 12 percent of the remaining frogs exhibit the green-skin phenotype. If the population is now in Hardy-Weinberg Equilibrium, what will be the frequency of the green-skin allele in the next generation? Provide your answer to the nearest hundredth.

[@Punjabibahman]

Awesome mate

[@audreymaemoncada3970]

Switched P and Q

[@noahfraser395]

+Audrey Mae Moncada Hey

[@aneatrice28]

This guy is a genius.

[@hppyemogrl101]

isnt q supposed to represent the ressicive allele?

[@randiir4185]

Can anyone please explain the math in this video? I can't understand these conversions from squared 0,09 to 0,3 than to 30%, as it is at 9:40

[@tbplc]

this video was so helpful oh my god

[@ben-l-6234]

This should really help. Thanks!

[@samheckle]

Preciate it bud, would be awsome if you would have gone into detail about the mathematics of 2pq like you did p and q squared though. i was able to figure it out myself though.

[@nowheretogobutup]

Fine Arts majors should e warned before enrolling in a class that involves math. Even a little bit. This was a huge help. Seriously, you have no idea.

[@TheTamorres]

why are we multiplying the probabilities rather than adding them?

[@soccergalsara]

Nice video, isn't proportion more appropriate terminology than frequency however? (where frequency = proportion x no. in population).

[@Tictactoe247]

If the population is now in Hardy-Weinberg equilibrium it should be relatively constant and so it shouldn't change from one generation to the next. If the phenotype for green skin is 12% and this is stable q2= 0.12. The square root of q2 to the nearest hundredth is 0.35, so q, the frequency of the green skin allele will be 0.35. Hope this helps.

[@shanao9960]

its good that you explained pretty clear. but the book and test are mostly indicated "p" is dominate gene allele and "q" is recessive allele. so i dont wanna comfuse myself so i dont wanna continue watching it. thx though

[@virupannamedikinal]

Thank you so much

[@Kago6267]

Yes but you can personally assign a meaning to a pronumeral. E.g. Where a= dominant allele and A=recessive.

[@shiilovesdogs]

how did he randomly get 75% and 25%? I dont see where the percentage is coming from, can someone explain? :/

[@joeldsouza2]

thx dude. colleage lecture are loooooooooooong

[@BethTheKilljoy]

Brilliant!

[@raid517]

I don't get it. If the allele frequency is 75% V's 25% and you have a probability of 50:50 of inheriting either Bb, or bb genotypes, then a BxB genotype is surely impossible in this scenario?

[@lukascocco]

yea it should because P is for the dominant allele and q is for the recessive one!

[@VidUploDer]

@Mrkleenupguy but this is a formula and people might still get confused about it , so it's better to follow the way Hardy-Weinberg put it although it dosen't make a difference ^_^ and thanks for the nice video MR.Khan